Heat exchanger



A. 5. BUTT AT EXCHANGIER 5 eets-Shet 1 Filed March 11; 1957 Q a a a a aa a 2 mm 6 3 a a 5 v INVENTOR,

I N e. BUTT I BY ATTORNEYS Jan. 20, 1959 v A. G. un "2,869,835

HEAT EXCHANGER 5 Sheets Sheet 2 Filed Mar ch 11, 1957 INVENTOR.

ALAN Gal/ r ATTORNEYS A. G. BUTT HEAT EXCHANGER Jan. 20, 1959 FiledMarch 11, 1957 3 Sheets-Sheet 3 INVENTOR.

ALAN G. BUTT ATTORNEYS United States Patent HEAT EXCHANGER Alan G. Butt,La Crosse, Wis., assignor to The Trane Company, La Crosse, Wis., acorporation of Wisconsin Application March 11, 1957, Serial No. 645,070

Claims. (Cl. 257-445) This invention relates to heat exchangers andparticularly to heat exchangers having spaced metallic plates formingpassages for the flow of fluids.

Such heat exchangers have had various boundary means for closing thespaces between plates along the edges of the plates to form envelopesfor the passage of fluids. It has been a problem with heat exchangers ofthis type to braze or weld a header to the heat exchanger core.

It has been customary in the prior art to attach the headers to acompleted core. With such a procedure it is diflicult to provide a' goodseal between the header and the core, and there is danger of heating thecore to the extent'that welded or brazed joints in the core are weakened or even destroyed.

When heat exchangers are put in operation forces are transmitted fromthe headers to the core. These forces may be due to expansion andcontraction, or to the suspension of the heat exchanger. In some casesthe heat exchanger is suspended from its headers. When the exteriorwalls of the core of the heat exchanger are of thin material, they areincapable of withstanding the forces transmitted from the headers.

It is an object of this invention to provide a heat exchanger in whichstructural members of the core extend outwardly from the walls of thecore and are brazed or welded to the headers to provide a header to corejoint of high strength and rigidity.

; It is another object of the invention to provide means on the core ofthe heat exchanger for locating and holding the header on the coreduring the brazing or welding operation.

It is still another object of the invention to provide interlockingmeans between the header and the core of a heat exchanger to improve theseal therebetween.

Other objects and advantages of the invention will appear as thespecification proceeds to describe the invention with reference to theaccompanying drawings in which:

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tangular parting sheets 14 have upwardly extending flanges 16 alongtheir edges except at the headers 10 and 11. A plurality of envelopecomponents in the form of rectangular parting sheets 18 have downwardlyextending flanges 20 along their edges except at the headers 10 and 11.The parting sheets 14 and 18 are arranged alternately one above theother in pairs having their flanges 16 and 20 extending toward eachother to form envelopes 21. In the envelopes 21, between parting sheets14 and 18, are longitudinal corrugated fin plates 22 and transversecorrugated fin plates 24. These fin plates 22 and 24, and the partingsheets 14 and 18 form passageways for conducting the fluid in acircuitous path from header 10 to header 11 as shown by the arrows inFig. 4.

The envelopes 21 are held in spaced relationship by a plurality ofspacers in the form of channels 26 which serve to space the partingsheets 14 and 18 which they contact. It should be understood that thesechannels 26 may be more closely spaced if it should be desired toincrease the heat transfer surface area in these passageways and thatthese spacers 26 may be in the form of corrugated fin plates similar incross section to fin plates 22.

The envelopes 21 have strips 28 extending between the fin plates 22'andthe flanges 16 and 20. The strips 28 also extend between the fin plates24 and the flanges 16 and 20. As shown in Fig. 4, one strip 28 extendsfrom theheader clip 38 along the side of the core adjacent the dischargeheader 13, thence along the end of the core and outwardly into headerclip 30. Another strip 28 extends from header clip along the side of thecore ad jacent to header 12, thence along the end of the core andoutwardly into header clip 32. The strip 28 is held against the flanges16 and 20 by the fin plates 22 and 24.

- Referring to Figures 5 and 6, a plurality of bars 34 extend betweenthe envelopes 21 at the ends of the core of the heat exchanger. Oneseries of bars 34 extend from within header clip 36 along the end of thecore and Fig. 1 is a perspective view of the complete heat exchanger ofthis invention;

Fig. 2 is an end elevational view of the heat exchanger; Fig. 3 is aside elevational view of the heat exchanger; Fig. 4 is a sectional viewtaken on line 4-4 of Fig. 2; Fig. 5 is a sectional view taken on line5-5 of Fig. 2; Fig. 6 is an enlarged sectional view taken on line 6-6 ofFig. 4 showing the parts prior to brazing;

Fig. '7 is an enlarged partial view taken on line 7-7 ofkFig. 5 showingthe parts prior to brazing.

And Fig. 8 is an enlarged sectional view similar to Fig. 6 showinganother modification of this invention prior to brazing.

Referring to the drawings the heat exchanger has a supply header 10 anda discharge header 11 extending from opposite ends of the core of theheat exchanger for conducting a first fluid. A supply header 12 and adischarge header 13 extend from opposite sides of the core of the heatexchanger for conducting a second fluid.

A plurality of envelope components in the form of recinto header clip38. A second series of bars 34 extend from within header clip 40 alongthe end of the core and into header clip 42.

A top outside sheet 44 is superimposed on the uppermost parting sheet18. This top outside sheet 44 has upwardly extending flanges 46 and 48forming part of headers 10 and 11 respectively and upwardly extendingflanges 50 and 52 forming part of headers 12 and 13 respectively.

A bottom sheet 54 is superimposed on the outside of the lowermostparting sheet 14. This bottom sheet 54 has downwardly extending flanges56 and 58 'forming part of headers 10 and 11 respectively and downwardlyextending flanges 60 and 62 forming part of the headers 12 and 13respectively.

In the modification shown in Fig. 8 channels 64 ex tend along the sidesof the heat exchanger in place of the bars 34 of the first form of theinvention disclosed in Figs. 1-7. ,In other respects the heat exchangerof the modification of Fig. 8 is constructed the same as the first formof the invention shown in Figures 1-7.

The manner in which the heat exchanger is produced will now bedescribed. The parts are all placed in their proper positions withbrazing 'foil or powdered brazing material between the surfaces to bejoined. The brazing foil or brazing powder melts at a temperature lowerthan the melting point of the elements of the heat exchanger. I preferto use a brazing foil. A sheet of brazing foil is placed between eachparting sheet 18 and the fin plates 22 and 24. A second sheet of brazingfoil is placed between each parting sheet 14 and the fin plates 22 and24. These sheets of brazing foil extend along the inside surfaces of theflanges 16 and 20 and outwardly through the gap therebetween. Smallspots of adhesive may be used between the sheets of brazing foil and theparting sheets 14 and 18 to prevent movement prior to brazing. Braz- 3.ing foil is also wrapped around the bars Maud the contacting surfaces ofthe channels 26. A suitable adhesive may be used to hold the foil inplace prior to brazing. It should be understood that this adhesiveevaporates completely during, the brazing operation. The top and bottomoutside sheets 44 and 54 contact the header clips 30, 32, 36, 38, 40,and 42. Adjacent these points of contact additional brazing material isused.

The assembled elements of the heat exchanger are held in place by a jig.The jig and the elements therein arethen placed in a furnace having areducing atmosphere such as hydrogen. The assembly is heated in thefurnace to a temperature suflicient to melt the brazing foil thusjoining all the elements of the heat exchanger into a unitary structure.

Although specific embodiments are shown and described itshould beunderstood that certain changes may be made without departing from thespirit of the invention and I desire to be limited only by the claims.

I claim:

1. A heat exchanger for two confined fluids comprising a plurality ofenvelope components stacked one above the other and forming passagewaysfor one fluid, members extending between said envelope components alongtwo opposite sides to space said envelope components and to provide apassageway for a second fluid, channel shaped header sides secured tosaid envelope components, said members extending into and being securedto the channels of said channel shaped header sides and means extendingfrom said envelope components and extending between and being secured tothe ends of said header sides to form headers.

2. A heat exchanger comprising a plurality of horizontally disposedenvelope components arranged one above the other, first membersextending along and between portions of the peripheries of said envelopecomponents to define with said envelope components envelopes having aplurality of first inlet openings arranged one above the other and aplurality of first discharge openings arranged one above the other,second members extending between said envelopes and extending alongportions of the peripheries of said envelopes to close the spacesbetween said envelopes at said portions of the peripheries of saidenvelopes and to define with said onvelopes a plurality of second inletopenings arranged one above the other and a plurality of seconddischarge openings one above the other, channel shaped header sidessecured to said envelopes and said second members, a

top sheet and a bottom sheet secured to the top of the top envelope andto the bottom of the bottom envelope respectively, said top sheet andsaid bottom sheet having flanges secured to and extending between saidheader sides to form headers in fluid communicationwith said inlet anddischarge openings, said first and second members having ends extendinginto the channels of said channel shaped header sides and being securedthereto.

3. A heat exchanger comprising a plurality of horizontally disposedenvelope components arranged one above the other, first membersextending along and between portions of the peripheries of said envelopecomponents to define with said envelope components envelopes having aplurality of first inlet openings arranged one above the other and aplurality of first discharge openings arranged one above the other.second members extending between said envelopes and extending alongsecond pora seae'eie tions of the peripheries of said envelopes to closethe spaces between said envelopes at said second portions of theperipheries of said envelopes and to define with said envelopes aplurality of second inlet openings arranged one above the other and aplurality of second discharge openings one above the other, channelshaped header sides secured to said envelopes and said second members,means extending from the top of the top envelope and from the bottom ofthe bottom envelope and extendinga plurality of first inlet openingsarranged one above the,

other and a plurality of first discharge openings arranged oneabove theother, second members extending between said envelopes and extendingalong second portions of the peripheries of said envelopes to close thespaces between said envelopcs at said second portions of the periph-"cries of said envelopes and to define with said envelopes a plurality ofsecond inlet openings arranged one above the other and a-plurality ofsecond discharge openingsone' above the other, channel shaped headersides secured to said envelopes and said second members, means extending from the top of the top envelope and from the bottom of the bottomenvelope and extending between said channel shaped header sides to formheaders in fluid communication with said inlet and discharge openings,said first and second members having ends extending into thechannels ofsaid channel shaped header sides and being secured thereto.

5. A heat exchanger comprising a plurality of horizon tally disposedparting sheets arranged in pairs one above the other with one partingsheet of each pair having downwardly extending flanges along portions ofits peripheral edge and with the other parting sheets of each pairhaving upwardly extending flanges along portions of its peripheral edge,the flanges of the parting sheets of each pair of parting sheets beingin substantially abutting relationship, strips extending between theparting sheets of each pair and being arranged in overlappingrelationship with the flanges of said pairs of parting sheets to spacethe parting sheets of each pair and to close the spaces between theflanges of said parting sheets to provide first passageways for a firstheat exchange fluid, means extending between the pairs of parting sheetsalong portions of their peripheral edges to space each pair of partingsheets from the next adjacent pair of parting sheets and to providesecond passageways for a second heat exchange fluid, headers secured tosaid parting sheets in fluid communication with said first and secondpassageways, and channels on said headers receiving and being secured tosaid strips.

References Cited in the file of this patent UNITED STATES PATENTS2,368,814 Pagan Feb. 6, 1945 Burns et a1. Sept."4,' 1951

